1. Field
This invention relates to multi-purpose vehicles. Specifically, it relates to an improved light weight, highly efficient multi-purpose vehicle particularly adapted for underground digging and hauling applications.
2. State of the Art
Numerous multi-purpose vehicles are known. These vehicles typically employ an X-shaped, or box-shaped frame with a conventional cab on the front, and a cabin or bed attached along the length of the frame, such as the amphibious vehicle designed by Fletcher et al, U.S. Pat. No. 2,923,268. Generally, the conventional multi-purpose vehicle has forward steering wheels and rear drive wheels. When pulling heavy objects, a number of conventional vehicles may be harnessed together in series. This requires a long pulling space to accommodate the aligned vehicles connected in series. These harnessed vehicles are also difficult to turn and cause the rear vehicles to run in the tracks left by the forward vehicles; often times resulting in poor traction of the trailing vehicles. The aligned vehicles, when harnessed, generally move in a longitudinal direction. Non-pivoting wheels of conventional vehicles do not allow significant sideward movement, which makes it necessary to uncouple and recouple the vehicles where it is necessary to move the load laterally.
To shorten the turning radius of conventional vehicles, articulated vehicles, such as those described in Hutt, U.S. Pat. No. 4,249,629, and Domenighetti, U.S. Pat. No. 3,914,065 have been utilized. In other applications, a series of carts pulled by a main drive vehicle may be employed, such as the Fire Fighting and Rescue Apparatus described by P. F. Cummins, U.S. Pat. No. 3,169,581. Although these articulated vehicles enable a series of harnessed vehicles to turn in a shorter radius, they do not solve the problem of the rear aligned vehicle's poorer traction as it travels in the same tracks left by the forward vehicles.
The confined working space in underground mines also requires compactness in self loading hauler (SLH) vehicle designs. As a result, SLH vehicles tend to have a length slightly greater than a light hauling design vehicle, with a length greater than the combined width and height of the vehicle. The excessive length is tolerable in a majority of underground operations since the drifts (tunnels) are long in comparison and have a narrow width and low height. The excessive length of the SLH contributes to counter-balancing the oversized payloads. However, the narrow width complicates turning and side slope stability. This requires judicious design of the basic frame structure and the location of the components within it. Low height is not only desirable from an operating stand-point, but is also necessary in order to improve the stability of the SLH.
Applicant's invention described below provides an efficient ergonomically designed SLH vehicle with a centrally located operator station. It has independent wheel drive and suspension which can move laterally, if desired, for greater mobility.
British Patent 1,203,338 incorporates a conveyor assembly running the length of the bed. It therefore is of a box-like shape rather than a U-shaped vehicle which can nest or interconnect for pulling and pushing articles. British Patent No. 1,059,656 uses a flexible articulated frame shown in FIG. 5, which lifts and bends during lifting to scoop earth. British Patent No. 1,059,656 also incorporates a conveyor system into its bed for materials handling and movement.
Muotka et al, U.S. Pat. No. 3,520,432 utilizes a box frame which requires a Blade 4 to rearwardly transport materials to the rear of the bed. Quenzi, U.S. Pat. No. 4,505,638 is another example of a box frame, utilizing a horizontal pair of tracks along which its bucket travels. This loading movement of the bucket action differs from applicant's as described below.
Moehr, U.S. Pat. No. 3,306,478 is another example of a low profile, self-loading hauling and dumping vehicle. Kress, U.S. Pat. No. 4,026,430 is a mobile carrier for large scrap steel carrying boxes. Wardle, U.S. Pat. No. 2,795,872 is a carry-all with claw loading scraper apron to assist in loading. Wilson, U.S. Pat. No. 3,235,983 is another earth moving apparatus. Galis, U.S. Pat. No. 3,826,387 is a self loading and self-propelled haulage vehicle. Niva, U.S. Pat. No. 4,556,356 is a U-frame truck for handling and transportation of containers or receptacles. Robb, U.S. Pat. No. 2,679,119 discloses an auxiliary scraper and loading apron. Bodine, U.S. Pat. No. 3,030,715 discloses a sonic wave earth digging and moving machine. Trieschmann, U.S. Pat. No. 3,273,732 is a self-loading vehicle and dump gate therefore. Le Tourneau, U.S. Pat. No. 1,891,266 discloses a scraper. Lichtenberg, U.S. Pat. No. 2,654,165 discloses a carry-type scraper with front digger moving means. Countryman, U.S. Pat. No. 3,937,345 is a shovel loader with ejector bucket. Shackley, Canadian Patent No. 681,266 is a vehicle provided with a dragline loader. Cited for general interest is Cohen, U.S. Pat. No. 4,065,825, and Nishibori, Japan No. 62-125952 showing an all wheel independent steering gear.